FILE - In this Friday, Oct. 17, 2014 file photo, Oscar Pistorius is escorted by police officers as he leaves the high court in Pretoria, South Africa. (AP Photo/Themba Hadebe, File)

(NBC) — Double-amputee Olympian Oscar Pistorius’ sentence for the murder of girlfriend Reeva Steenkamp was extended to 13 years and five months by a court Friday.

South Africa’s Supreme Court of Appeal increased the sprinter’s prison term after prosecutors successfully argued his original sentence of six years was “shockingly lenient.”

The so-called “Blade Runner” was not in court for Friday’s ruling where the court handed down the minimum 15-year sentence prescribed for murder in South Africa, and subtracted the time Pistorius had already served in prison.

Pistorius, 30, fired a gun multiple times through a closed bathroom door on Valentine’s Day in 2013. The athlete said he thought Steenkamp was a dangerous intruder.

The model and law graduate’s parents did not attend the hearing but welcomed the news.

“Their trust in the justice system has been confirmed this morning,” said Tania Koen, a spokeswoman for Steenkamp family. “There has been justice for Reeva. Reeva can now rest in peace.”

It was the second successful challenge from prosecutors. In 2015, they overturned Judge Thokozile Masipa’s original verdict of culpable homicide — or manslaughter — and secured a murder conviction.

Masipa then sentenced Pistorius to six years in prison, a term just one year longer than her original sentence for manslaughter. The country’s National Prosecuting Authority quickly said it would appeal, calling that term “disproportionate,” “shockingly too lenient” and “an injustice.”

There is no death penalty in South Africa.

Pistorius, who is in a prison near the capital, Pretoria, was treated in hospital last year for injuries to his wrists.